1. Field
The present embodiments relate to a perpendicular magnetic recording head that performs a recording operation.
2. Related Art
A magnetic head device includes a longitudinal recording (in-plane recording) magnetic head device that applies a magnetic field parallel to a plane of a recording medium thereto to perform a recording operation, and a perpendicular magnetic recording head device that applies a magnetic field perpendicular to a plane of the recording medium thereto to perform a recording operation. The perpendicular magnetic recording head device is further suitable to increase the recording density.
Conventionally, the perpendicular magnetic recording head has a structure in which a main magnetic pole layer and a return path layer are laminated with a non-magnetic insulating layer therebetween at a surface facing a recording medium. The main magnetic pole layer and the return path layer are magnetically connected to each other at the rear of a surface facing a recording medium in a height direction. Coil layers that applies a recording magnetic field to the main magnetic pole layer and the return path layer are provided in the gap layer.
When current is supplied to the coil layers, a recording magnetic field is induced between the main magnetic pole layer and the return path layer. In this case, the recording magnetic field is perpendicularly applied to a hard film of the recording medium from the front end surface of the main magnetic pole layer exposed to the medium facing surface, and the recording magnetic field returns to the return path layer through a soft film of the recording medium. Accordingly, a magnetic recording is performed at a portion facing the main magnetic pole layer.
In the above perpendicular magnetic recording head, the main magnetic pole layer, the gap layer, and the return path layer may be formed, for example, as follows. The gap layer made of Al2O3 and a resist layer are formed so as to be subsequently laminated on the main magnetic pole layer made of a magnetic material. The resist layer is removed from the end surface serving as the medium facing surface to a position as a predetermined depth dimension by using photolithography process (exposure, development), and the gap layer is exposed to the removed region. The depth dimension of the exposed gap layer is a throat height. In addition, a dry etching (milling) as plating pre-treatment is performed, a plated underlayer is formed on the gap layer and the resist layer, and the return path layer is formed on the plated underlayer by plating. The formation of the gap layer and the return path layer are accomplished.
The above-mentioned perpendicular magnetic recording head and a method of manufacturing the same are disclosed in JP-A-2005-122831.
In the above-mentioned perpendicular magnetic recording head, the thickness of the gap layer, for example, the gap distance is an important parameter that determines the writing performance (recording magnetic field strength and recording resolution) of the perpendicular magnetic recording head. Accordingly, it is required to define the gap distance.
In a manufacturing method of the related art, since the gap layer made of Al2O3 is eroded by the alkali developing solution used in the photolithography process in removing of the resist layer, and the gap layer is cut by the dry etching, which performs as a pre-treatment in forming of the plated underlayer or the coil layer, the film thickness of the gap layer becomes thinner in accordance with the passage of the manufacturing process, and it is difficult to control the gap distance at the accomplishment state of the head.